Electromagnetic regulator



March 4, 1941. F MENZEL 2,234,158

ELECTROMAGNETIC nEGULAToR Filed April 15, 1959 Patented Mar. 4, 1941PATENT OFFICE 2,234,158 ELECTROMAGNETIC REGULATOR Friedrich Menzel,Stuttgart, Germany, assigner to Robert Bosch Gesellschaft mitbeschrnkter Haftung, Stuttgart, Germany" Application April 15, 1939,Serial No. 268,115 In Germany April 22, 1938 3 Claims. (Cl. 171-229) Thepresent invention relates to an electromagnetic regulator fordynamo-electric machines of electric installations including thosesuitable for use on vehicles, and having a resistance which mayperiodically be switched in series with the exciting winding of thedynamo.

In the known regulator constructions of installations of this type theresistance to be switched in before the exciting winding is formedmostly as a special or separate part of the apparatus, and is ofsuitable material which for example is tted in the base of theregulator.

It is also known, in regulators having only one regulator contact, whicheffects the periodic switching in of the resistance before the excitingwinding, to apply this resistance'in the form of a demagnetisingwinding, or so called bucking coil,

beside the voltage coil on the electromagnet of the regulator.

According to the present invention a component part of the voltage coilof the regulator acting wholly in the same direction serves as theresistance to be switched in before the exciting winding of the dynamo.

For this purpose the voltage coil of the regulator is tapped at such aplace, that at the instant of regulation the same ampere windings areeffective at all positions of the regulator contact.

'Ihe arrangement according to the present invention has the advantagesover the known construction with a resistance in the form of a tremblercoil that firstly the resistance need not be wound as a special orseparate coil, but can be wound as a unit with the voltage coil of Whichit forms a part and secondly the construction is suitable for regulatorswith several regulator contacts whilst the known regulators can only beconstructed with one regulator -contact.

The invention is more particularly described with reference to theaccompanying drawing `which shows schematically by way of example,

one form of construction voltage regulator for dynamos suitable for use'on automobiles or other vehicles.

In the drawing the armature I and an exciting winding 2 form the dynamo.A voltage coil 4 wound about a magnet core 3 of the voltage regulator isdivided at the place of division 5 into parts 4I, 42 in such a mannerthat the part 4I can serve as a switched in resistance for the excitingwinding 2.

An armature 6 carries regulator contacts 'I, 8 respectively adapted formake and break with opposed xed contacts 9 and III. A spring II operatesto draw the armature 6 into that position of rest in which the contacts1 and 9 are closed. For the sake of completeness an automatic charg-`ving switch I2 and a battery I3 are diagram-"5 matically shown in thedrawing.

The number of windings of the parts 4I and 42 of the voltage coiltogether with their resistance values are so chosen that in each of thesubsequently described regulation positions of l0 the contacts 'I, 8, 9,Il) the same number of ampere turns are active. The voltage coil 4 canthereby consist ofv parts composed of the same or different material.The voltage is regulated in a manner known in bucking regulators.

On the putting into operation of the dynamo the part 4I of the voltagecoil serving as a switched in resistance is short circuited by theclosed contacts 1, 9. 'Ihe voltage evolved by the dynamo assumes thevalue commensurate with the resistance of the exciting winding 2. Thusonly the part 42 of the voltage coil 4 lies at the voltage evolved bythe dynamo under these conditions.

If on account of increasing speed of the dynamo the voltage andtherewith the current flowing through the part 42 has attained apredetermined value, then this current together with the windings of thepart 42 requires a definite number of ampere turns at which the voltageregulator attracts its armature 6 against the pull of the spring .II,and thereby separates'the contacts 'I and 9, so that all the regulatorcontacts are open. At this moment when the part 4I is switched in beforeand in series with the exciting winding 2, to which the part 42 liesparallel, the same ampere turns are active as in the foregoingregulation position with closed contacts 1 and 9, by reason of thecorresponding choice of the resistance and number of windings of theparts 4I and 42 as a result of the partial current flowing through thepart 42, and of the total current flowing through the part 4I.

At higher speeds of rotation the armature 6 closes the contacts 8, I0,whereby the exciting 45 winding 2 and simultaneously the part 42 of thevoltage coil 4 are short circuited. In the current ,circuit there liesnow only the part 4I which commensurate with its number of turns and itsresistance value, together with the current flowing through it at thisinstant', has again in this contact position, the same number of ampereturns as was attained in the foregoing regulation positions.

By the invention is thus obtained a regulator,

i... we,

in which, while avoiding a special or separate switched in resistancefor the exciting winding, a part of the voltage bobbin serves as aswitched in resistance and which, in spite of this, has the sameelectromagnetic force in each regulating contact position.

I declare that what I claim is:

l.` The combination, with a dynamo-electric machine, having an excitingwinding, for electric installations on vehicles, of an electromagneticregulator comprising a magnet core, a voltage coil wound about saidmagnet core and acting wholly in the same direction of magnetization, anamature, a contact operated by said armature, a fixed contact in theelectric circuit oi' said machine for engagement with the contactoperated by said armature, and a conductor lead extending from saidexciting winding and the contact operated by said armature to a point ofsaid voltage coil intermediate the ends thereof to divide said coil intotwo component parts, one o! which component parts perates as aresistance switchable periodically in series with said exciting windingby said contacts.

2. A regulating system for dynamo-electric machines such as for lightingand charging installations on vehicles comprising, in combination, adynamo-electric machine having an exciting winding, a circuit includingsaid winding,

and an electromagnetic regulator in said circuit.

and comprising only one voltage coil having a component part adapted toact as a resistance and wholly in the same direction magnetically assaid voltage coil, said regulator also including an armature andcontacts controlled thereby for periodically connecting said resistancein series withV said exciting winding.

3. In a regulating system for dynamo-electric- FRIEDRICH MENZEL.

